Let-back for loom take-ups



March 15, 1932.

Fig. 1.

c D. BROWN 1,849,221

LET-BACK FOR LOOM TAKE-UPS Filed July 19, 1930 \nvenTor.

V Carl D. Brown Anya.

mechanism is to be arrested as, for example, through the action of a filling fork when the filling breaks during the weaving operation.

All of the mechanism thus described is well known and familiar to those skilled in the art. During the normal weaving operation the clutch, parts 20 and 21 are in engagement and the take-up roll 4 is being positively driven to effect take-up from the driving member or shaft 9 through the driven member or pinion 10 and the intermediate train of gearing extending to the take-up shaft 3. When take-up action is to be arrested and letback take place, the clutch member 21 is automatically moved to the left in opposition to its spring 23 by the lever 22 and thus the driving member is disconnected from the driven member of the mechanism.

In the present invention a let-back actuator is provided, a preferred construction of which is shown in detail in Figs. 3 and 4. This device is in engagement with the train of gearing interposed between the driven member of-the take-up roll and is preferably lo cated' at the end of the train-of gearing remote from the take-up roll. I It is conveniently mounted upon the bracket 13, which bracket, as is usual, is supported on the shaft 9 and adj ustably secured to the loom frame so as to provide for changing the size of gears employed in the gear train. I

This let-back actuator, in the specific form illustrated, comprises a journal {stud 24 mounted in and projecting from the bracket 13; a cup-shaped spring case 25 having a hub 26 journalled on the stud 24:; a coiled spring 27, similar to a clockspring, concentrically mounted in the spring case and secured at its inner end, as by the pin 28, to the bracket 13 and frictionally engaging at its outer end the interior of the spring case; an annular cover 29 secured by the screws 30 to the end of the spring case and enclosing the spring; a pawl 31 journalled on a stud 32 screwed intothe spring case near its periphery and parallel with the stud 24 and normally pressed inward by a spring 33; a pinion 34 journalled coaxially with the spring case and for that purpose conveniently journalled on the hub 26 ofthe spring case; and a ratchet 35 on the pinion 34and cooperating with the pawl 31.

A washer 36 and pin 37 on the outer end of the stud 24 hold the parts in position. The pinion 34 intermeshes with the gear 11.

It will thus be seen that'as they train of gearing is driven to effect the take-up action of the take-up mechanism, the pinion 34 will be driven by the gear 11 and act through the pawl 31 to drive the spring case, thus wine ing up the spring until the frictional engagement between the outer end of the spring and the spring case is overcome and slippage takes place. When now the driving member or element such as the shaft 9 is disconnected from the driven member or element such as the-take-up roll is positively driven in the reverse direction, quite independently of the pull on the warps, to effect a definite and required amount of let-back. Any suitable connection may be employed between the spring case 25 and the pinion 34, but the pawl and ratchet mechanism illustrated permits relative rotary adjustment of the spring case with respect to the pinion and transmits the spring-actuated movement of the spring case to the pinion in all positions. 7

There is thus provided a simple and efiicient mechanism by means of which, when the driving member of the take-up mechanism is disengaged from the driven memher, the driven member is driven in a reverse direction to a limited extent thus positively toelf'ect let-back.

Having thus described the invention, what is claimed as new, and desired tobe secured by Letters Patent, is: I

.1.v Take-up mechanism for a loom comprising a take-up roll, a driving member, a train of gearing between said driving member and take-up roll, means to disengage the driving member from said gearing to arrest take-up, a pinion intermeshing the gearing, a spring case, the said pinion and spring case being concentrically journalled on the 100m frame, a coiled spring concentrically mounted in Said case and secured at one end to the frame and at the other end frictionally engaging the case, and a connection between the case and pinion, the said pinion acting during take up to rotate the case and store up power in the spring and the said spring acting upon disengagement of the driving member to rotate the pinion in reverse direction to effect let-back. I 1 1 2. Take-up mechanism for a loom comprising theconstruction defined in claim 1 in which the connection between the case and pinion is in two parts co-opcrating to permit relative rotary adjustment of the case and pinion.

3. Take-up mechanism for a loom comprising the construction defined in claim 1 in which the connection between the case and pinion comprises a ratchet wheel on the pinion and a spring-pressed pawl on the case co-operating with the ratchet wheel to permit relative rotary adjustment and to transmit the spring-actuated movement of the case to the pinion.

thep

7 4. A let-backactuat0r fortake-u'p mecha nism for a loom comprising a journal stud I mounted in the loom frame, a spring case journalled on the stud, a coiled spring mounted concentrically in the spring case secured at one end to the frame and'at the other end frictionally engaging the case, a pawl pivotally mounted on the case, a pinion journalled coraxially with the spring case and a ratchet on the pinion co-operating with awl. 5. Alet-back actuator for take-up mecha-' nism for a loom comprising a journal stud mounted in the loom frame, aspring case having a hub journalled on the stud, a coiled spring mounted concentrically in. the spring case secured at one end to the frame and at the otherend frictionally engaging the case, a pawl pivotally mounted on the case,.

a pinion journalled on the hub of the case,

7 anda ratchet on the pinion co-operating with the pawl.

In testimony whereof, I have signedmy name to this specification. a

' GARL'D. BROWN. 

